Thread

Need help pointing to strange video problem on SE/30

Need help pointing to strange video problem on SE/30 Hardware 114 posts Apr 8, 2013 — Jan 31, 2014

#31 Tue, 30 Apr 2013 - 01:57

I would like to update that I successfully fixed the original issue I started the thread with.

I first swapped all the removable chips one by one from another working se30, no luck.

Thanks to uniserver for keeping an eye out for the solution and asking for pictures.

It was a "simple" one wire fix.

http://s20.postimg.org/z1w7b8lpp/se30.jpg

See the original thread posting the photo here:

viewtopic.php?f=7&t=21005&p=202535#p202535

If anyone has a spare video rom for an se30 please contact me. I have a damaged one in a different compact from an unrelated incident.

#32 Tue, 30 Apr 2013 - 12:18

Nice one !

#33 Wed, 1 May 2013 - 07:45

anyone want to take a stab at a patch i could preform to remove this video issue?

other then this video issue, this machine works 100% SCSI/FDD/Sound.

Screen shot 2013-05-01 at 2.33.26 AM.png

here is a shot of the board

#34 Wed, 1 May 2013 - 09:59

following the schematic , between UE8 the VID lines to UC6 and UC7 just don't make sense, the only pins that really make continuity is pin 2 of UE8 and PIN 2 of UC7, and pin 3 of UE8 and pin 3 of UC7, none of the rest of the pins seem work(continuity) . may be I have a different revision or something.

witch seems strange because it appears only one pixel is out of the 7 data lines.

Screen shot 2013-05-01 at 4.57.00 AM.png

#35 Wed, 1 May 2013 - 23:05

My reasoning from my very limited understanding of the video system is that only the last pixel is incorrect, all other 7 are ok therefore the problem must be between RAM and shift register, assuming the RAM's are ok. If it were an addressing issued before the RAM's, it would be at least two faulty lines as the RAM is interleaved? Does that make sense to anyone? Now I'm not too sure myself anymore

.

As the first 7 pixels are ok, VID0 to VID6 must be ok, so I assumed that there must be a problem with VID7. As VID7 on UC6 RAM (pin23) is only connected to VID7 on UE8 shift register (pin 14) I thought this would be the first place to look. As the thick line labelled VID(0-7) is in reality 8 individual tracks, the others shouldn't be connected, just as you say, so only corresponding VID numbers are connected (VID0 to VID0, VID1 to VID1 etc).

Hmm that could be it, probably too much to ask for though, is it?

#36 Wed, 1 May 2013 - 23:42

The problem could also be in the shift register itself, I've had logic ICs fail in such a way that inputs were dead, as well as some interesting internal faults that caused the outputs to not behave the way I expected.

Occasionally I'll take a probe connected to Vcc or Gnd via a 100 ohm-ish resistor and touch it to various input pins to force them high or low and observe the effect on the circuit. If you force one of the shift register inputs high, I would expect a row of light or dark pixels. When you find the pin that affects the dead columns you are seeing, or discover that none of them do, that will give a pretty good clue as to where the problem is. A logic probe can be very useful for this sort of fault tracing too.

#37 Sun, 5 May 2013 - 18:12

i hate my self i have been counting the pins on the chips wrong.

after you count the side that starts with one i was continuing my counting across from pin 1 on the other side of the chip.

that is why nothing was making sense to me.

#38 Sun, 5 May 2013 - 18:16

sure enough UE8 pin 14 (witch is video 7, last pixel) to Pin 23 to UC6, gets no continuity.

#39 Sun, 5 May 2013 - 18:38

OK the Gangster Pin stripe SE/30 i got from insaneboy finally is all working.

also thanks genie-mac!

and thanks techkinght!

Thanks to CC_333 as well ,

would like to also Thank james1095

#40 Sun, 5 May 2013 - 20:04

Nice one!

#41 Wed, 8 May 2013 - 22:28

thanks man you were a great help!

#42 Thu, 9 May 2013 - 01:23

Woohoo!!! Nice work.

#43 Thu, 9 May 2013 - 03:54

Hey what can I say this forum rules...

Mega smart, Determined, Generous people!

fixing that really made me happy.

#44 Thu, 9 May 2013 - 15:18

Glad I could help. Hope it wasn't just beginner's luck

#45 Thu, 9 May 2013 - 15:46

You guys are an inspiration! Now i'll have to go take a closer look at my board with gangster pinstripes.

#46 Sun, 19 May 2013 - 16:54

came across another SE/30 gangster pinstripe issue,

this one needed 3 lines ran.

Screen shot 2013-05-19 at 11.52.02 AM.png

Screen shot 2013-05-19 at 11.49.58 AM.png

Used the VOM, followed the schematic, it's good to go.

Vid 0, Vid 3, Vid 6

#47 Mon, 20 May 2013 - 20:44

This is getting too easy

#48 Mon, 20 May 2013 - 20:49

well I still have one that is dead, It acts like there is no rom simm inserted,

do you have a magic trace fix for that one ?? lol

the cap near the battery leaked real bad causing corrosion on many of the via's surrounding it.

#49 Tue, 21 May 2013 - 08:17

You know that this is the type of situation that makes me start to think that replacement is better than restoration, right? Not uniserver, he's Marty McFly. Can't back down from a challenge

#50 Wed, 5 Jun 2013 - 04:27

Here is another Gangster pinstripe SE/30 video fix.

This one also needed a new ADB Fuse. The ports on this board are BEAT, this thing was well USED...

ITs all good now ... works great now. Protected with Anti Corrosion/Polish Treatment.

#51 Tue, 11 Jun 2013 - 01:42

Awesome! So how many of these video issues have you fixed Uniserver!?!

I pulled this post back up because I am about to embark on trying to fix a scsi issue on another se/30

#52 Tue, 11 Jun 2013 - 02:14

just 3 so far.

its really a great feeling when they work right again.

i have that video rom for you. its right here. just come over after 6pm so i will be here man.

Charles

#53 Wed, 12 Jun 2013 - 22:09

for SCSI issues I would suggest watching techknights video on youtube.

Bob_at_Easel.jpg.d4cb8077dd43f42a7d307ca38e296ef5.jpg

i just realized bob ross died at age 52, man what the heck, these great people… so young..

#54 Thu, 27 Jun 2013 - 03:40

for SCSI issues I would suggest watching techknights video on youtube.

And we have people like you that take the time and fix these machines to keep them running, to fill my shoes persey, as I dont have time to do it much anymore. But I digress. I did manage to fix that machine, But I got a board from JDW that acts as if no ROM simm is inserted either. it passed all continuity checks. I think the GLU is bad, as its not switching memory map allocations to access ROM at ADR 0.

#55 Thu, 27 Jun 2013 - 03:48

So far I have (2) SE/30 boards that do exactly that. they act as if the rom simm is not installed.

#56 Thu, 27 Jun 2013 - 15:46

Once I can save up enough I'm def. bringing my Classic II to Uniserver to get recapped, and if I can talk him into it, look at my video wobble issue, to see if the analog needs to be recapped, or it is some kind of magnetic interference issue.

Those of us within a reasonable distance are lucky to have him nearby.

#57 Thu, 27 Jun 2013 - 16:04

sure , no problem.

#58 Fri, 12 Jul 2013 - 00:17

No Problem.

Lemon Scented Pledge.

The Stuff works wonders.

#59 Sun, 14 Jul 2013 - 21:54

I love this thread. So am I right in assuming the wired traces bein run between IC's are basically just replacing existing printed circuit traces that have corroded out of continuity due to leaky caps etc??

#60 Sun, 14 Jul 2013 - 23:30

^Yep, essentially.

Hmmm, guess I need to pick up a can of Pledge while I'm out this afternoon...

-J